The primary long term goal of the proposed research is an improved understanding of how blood cells are affected by passage through extracorporeal systems. Within this general context the following specific subjects are being investigated: (1) flow-induced alterations of red cells, platelets and marcrophages; (2) effect of hemodialysis on membrane transport in the red cells of uremic blood; (3) mechanical properties of the red cell membrane and how these relate to molecular constituents and ultrastructure of the membrane; (4) oxygenation of blood in turbulent flow.